— : 


Issued  August  26,  1907. 

.  S.  DEPARTMENT   OF   AGRICULTURE 

/  OFFICE  OF  EXPERIMENT  STATIONS— FARMERS'  INSTITUTE  LECTURE  7 

A.  C.  TRUE,  Director. 


SYLLABUS 

OF 

ILLUSTRATED  LECTURE 

ON 

KOADS  AND  ROAD  BUILDING. 


BY 


THE  OFFICE  OF  PUBLIC  ROADS, 

U.  S.  DEPARTMENT  OF  AGRICULTURE. 


"..  'T  s\    ^L 


WASHINGTON: 

GOVERNMENT    PRINTING    OFFICE. 
1907. 


102-j  Issued   August  20,   1907. 

U.  S.  DEPARTMENT   OF   AGRICULTURE. 

OFFICE  OF  EXPERIMENT  STATIONS— FARMERS*  INSTITUTE  LECTURE  7. 

A.  C  TRUE,   Director. 


SYLLABUS 

OF 

ILLUSTRATED  LECTURE 

ON 

Roads  and  Road  Building 


BY 


THE  OFFICE  OF  PUBLIC  ROADS, 

U.  B.  DEPARTMENT   OF  AGRICULTURE. 


WASHINGTON: 

GOVERNMENT     PRINTING     OFFICE, 

19  0  7. 


PREF  VI'oKY    NOTE 


This  syllabus  of  a  Lecture  upon  Roads  and  Road  Building,  prepared 
in  the  Office  of  Public  Roads  of  the  United  States  Department  of 
Agriculture,  is  accompanied  by  forty-one  lantern  slides  illustrating 
the  topic.  The  syllabus  and  views  have  been  prepared  for  the  pur- 
pose of  aiding  fanners'  institute  lecturers  in  their  presentation  of  this 
subject  before  institute  audiences.  The  various  methods  of  road  con- 
struction given  are  those  suitable  for  country  roads  and  are  adapted  to 
different  sections  of  the  country  according  to  the  materials  available. 

The  numbers  in  the  margins  of  the  pages  of  the  syllabus  refer  to 
similar  numbers  on  the  lantern  slides  and  to  their  legends  as  given  in 
the  Appendix.  Those  in  the  body  of  the  text  refer  to  corresponding 
numbers  in  the  list  of  authorities  and  references. 

In  order  that  those  using  the  lecture  may  have  opportunity  to 
acquaint  themselves  fully  with  the  subject,  reference-  to  it-  recent 
literature  are  given  in  the  Appendix. 

John  Hamilton, 
Farmer^  InstituU  Specialist. 

Recommended  for  publication. 
A.  C.  True,  Director. 

Publication  authorized. 

James  Wilson.  Secretary  of AgricttUt 

Washington,  D.  C,  July  /.  1907. 

(2) 


ROADS  AND  ROAD  BUILDING. 


By  the  Office  of  Public  Roads. 


INTRODUCTION. 

View, 

Every  progressive  farmer  recognizes  the  advantages  which 
come  from  living  in  a  farming  community  supplied  with  a  sys- 
tem of  roads  passable  at  all  seasons  of  the  year.  Not  to  men- 
tion the  discomfort  and  loss  of  social  intercourse  resulting  from 
poor  highways,  he  can  estimate  in  dollars  and  cents  the  loss  he 
is  incurring  from  poor  transportation  facilities. 

The  farmer's  expense  of  hauling  is  greatly  increased  by  bad 
roads.     He  may  be  obliged  to  deliver  his  product  at  the  local  1 

shipping  point  when  prices  are  low  and  the  roads  passable,  or 
wait  for  a  better  market  and  run  the  risk  of  having  to  haul  over 
rough  roads  with  more  horses  to  the  wagon  and  a  much  lighter  2 

load.  The  expense  of  hauling  under  these  difficulties  may 
amount  to  double  or  even  four  times  the  normal  cost.1  a  A  large 
tonnage  of  perishable  merchandise  that  can  not  be  handled  with 
profit  when  hauled  over  poor  roads  would  be  put  in  motion  by 
improved  highwa}rs,  and  a  larger  profit  realized  on  many  prod- 
ucts which  are  now  moved  with  little  advantage,  thus  directly 
benefiting  both  the  producer  and  the  consumer.2  The  cost  of 
hauling  twelve  principal  crops  to  shipping  points  in  the  United 
States  during  the  crop  year  1905-6  has  been  estimated  by  the 
Bureau  of  Statistics  of  the  Department  of  Agriculture  as 
$72,984,000.3     This  excludes  crops  hauled  to  local  mills. 

Serviceable  roads  also  enhance  the  market  value  of  real  estate.  3 

From  figures  recently  compiled  in  the  Office  of  Public  Roads 
a  comparison  of  the  percentage  of  improved  roads  with  the 
acreage  values  of  farm  lands  in  the  United  States  has  been 
made.*  These  figures  show  that  the  average  percentage  of 
improved  roads  in  all  States  where  the  land  is  worth  less  than 
$20  per  acre  is  1.9  per  cent,  whereas  in  the  States  showing  an 
acreage  value  of  more  than  $20  improved  roads  constitute  an 
average  of  9  per  cent  of  the  total  mileage.  The  States,  there- 
fore, which  show  a  high  percentage  of  improved  roads  have  on 

a  Numbers  refer  to  list  of  references  on  p.  14. 
(3) 


the  average  a  much  liitj-li* - r  acreage  value  than  the  States  which 
-how  a  low  percentage.     Take  the  figures  from  Mississippi,  for 

instance,  the  farm  land-  of  thai  State  are  worth  on  the  avei 
only  $15.94  per  acre,  while  the  percentage  of  improved  roads 
is  0.38  of  1  pet- cent.  Contrasting  these  figures  with  those  for 
Indiana  we  find  that  the  farm  land-  in  that  State  are  valued  at 
$54.97  per  acre,  and  that  the  unproved  roads  constitute  35  per 
•  •ent  of  the  total  mileage.  While  the  quality  of  the  -oil,  near- 
ness to  market,  relative  population,  and  wealth  affect  the  price 

\  of  land,  these  figures   indicate   that   the   improvement  of   roads 

constitutes  a  mo-t  important  factor  in  the  enhancement  of  farm 
value-.      A    well-kept    farm    located    on   a    smooth,    hard    road. 

5         affording  quick    and    easy   access   t<»    market-,   schools,   and 
churches,  will  not  lack  ready  buyers  at  a  good  pri< 

In  comparing  the  percentage  of  road-  improved  with  the 
population  per  mile  of  road,  it  seems  evident  that  State-  having 
the  highest  percentage  of  improved  road-  have  the  largest  popu- 
lation per  mile  of  road.  Thus  serviceable  roads  are  a  factor 
in  encouraging  immigration. * 

METHODS  OF  CONSTRUCTION. 

The  method  of  road  improvement  will  vary  altogether  with 
the  use  to  which  the  road  i<  to  he  put  and  will  depend  upon  the 
money  and  material-  available.  It  is  impossible  to  give  esti- 
mates of  the  cost  of  roads  which  will  apply  to  all  parts  of  the 
country  alike,  as  these  details  will  vary  according  to  the  cost  of 
material-,  price  of  labor,  width  and  depth  of  road  surfaced,  and 
amount  of  grade. 

The  macadam  type  of  surfacing  is  well  adapted  to  main  ways 
connecting  centers  of  population  on  which  there  i<  a  moderate 
volume  of  travel.  The  load-  less  traveled  may  be  surfaced 
with  gravel.  Road-  of  Band-clay  and  of  burnt-clay  furnish  an 
economical  form  of  construction  in  localities  having  no  hard 
material-  available. 

LOCATION. 

Whatever  the  type  of  road,  proper  grades  and  drainage  are 
(S         of  the  utmost  importance.     All  grade-  should  of  course  b 

nearly  level  a-  possible.      However,  in  road   construction  little 
i^  ordinarily  done    beyond    reducing  the  hills  to  the  maximum 
7  grade  adopted  and   removing  the   irregularities   between    the 

hill-.      In  American  practice  the  maximum  grade  for  Important 
road-  has  been  generally  fixed  at  5  percent,  where  such  a  grade 
can  be  had  without  too  great  cost  for  cutting  and  tilling  and  for 
payment   for  damage  to  abutting  property.      By  .'.   per  cei 
meant  a   vertical    rise  of  .~>  feet  in    1""   feet  of    horizontal   dis- 


View. 

tancc.7  In  the  endeavor  to  secure  routes  covering  the  shortest 
distances  between  fixed  points  a  road  is  often  made  to  go  over 
a  steep  hill  instead  of  around  it.  Steep  grades  become  covered 
at  times  with  coats  of  ice  or  slippery  soil,  making  them  very 
difficult  to  ascend  with  loaded  vehicles  as  well  as  dangerous  to 
descend. 

DRAINAGE. 

The  surface  water  should  always  have  opportunity  to  drain 
from  the  roadway  as  quickly  as  possible,  and  water  should 
never  be  permitted  to  remain  under  a  road.  The  road  surface 
must  be  " crowned"  or  rounded  up  toward  the  center,  so  that  8 

there  may  be  a  fall  of  from  £  inch  to  1  inch  to  the  foot  from 
the  center  to  the  sides,  thus  compelling  the  water  to  flow  rap  9 

idly  from  the  surface  into  the  gutters,  which  should  be  con- 
structed on  one  or  both  sides  of  the  road.  The  fall  from  the 
center  to  the  sides  on  macadam  roads  need  not  be  so  great  as 
on  earth  or  gravel  roads.  To  prevent  the  washing  of  the  gut- 
ters into  deep  gullies,  they  may  be  paved  with  bricks  or  field 
stones,  or  side  drains  may  be  constructed,  consisting  of  narrow 
trenches  filled  with  broken  stones  or  small  gravel  stones,  with  10 
a  pipe  5  or  6  inches  in  diameter  near  the  bottom.  The  pipe  is 
carried  to  a  proper  outlet.  Sometimes  the  pipe  is  omitted  and 
the  entire  trench  is  filled  with  stones,  in  which  case  it  is  called 
a  "blind  drain."  Such  drains  serve  to  cut  off  the  subsurface 
water  before  it  can  get  under  the  road.  The  water  should 
never  be  carried  in  the  gutters  or  in  side  ditches  any  farther 
than  is  necessary.  When  the  volume  of  water  is  small  it  may 
often  be  conducted  across  the  road  in  tile  pipes  buried  suffi- 
ciently deep  so  as  not  to  be  broken  by  vehicles  upon  the  road. 
For  large  volumes  of  water,  culverts  of  rubble  masonry  or  11 
Portland  cement  concrete  may  be  built. 

EARTH  ROADS. 

Owing  to  the  absence  in  many  sections  of  the  country  of 
rock,  gravel,   or  other  hard  substances  with   which  to   build 
durable  roads  and  because  of  the  excessive  cost  of  such  material 
where  it  is  transported  from  a  distance,  the  majority  of  our 
public   highways   are   necessarily  earth  roads.     The   split-log       12 
drag  has  been  of  great  service  in  the  improvement  of  earth 
roads.     This  simple  implement  is  made  of  the  halves  of  a  split 
log  framed  together  by  wooden  braces  about  3  feet  in  length,       1 3 
so  that  the  split  surfaces  of  the  log  shall  be  in  front.     The  face 
of  the  drag  lies  at  an  angle  of  45c  with  the  line  of  the  road, 
thus  drawing  the  earth  toward  the  center.     The  rear  log  should       14 
follow  in  the  track  of  the  first.     Drags  should  be  used  just 


6 

15      after  rains  or  continued  wef  weather  to  smooth  the  earth  sur- 

M>      face  and  prevent   ruts  from  forming  to  hold  the  water.     The 

drag  not  only  smooths  the  road  but  crowns  it  and  puddles  the 

mad  bo  that  it  is  hard  when  dry.     These  drags  have  been  used 

1  «       with  success  on  day  or  water-holding  soils,  and  many  sections 

of  rural  roads  arc  maintained  by  the  use  of  thi>  implement 

IS        alone.      Every  fanner  should  own  one  and  after  a  rain  he  should 

spends  tVw  hours  dragging  the  road  adjacent  to  his  farm.     If 
there  are  many  depressions  to  till  the  drag  should  be  used  when 

L9  the  road  is  wet,  but  after  it  has  made  the  road  fairly  smooth  it 
gives  the  best  results  if  used  when  the  earth  begins  todry.     All 

20  stumps,  roots,  vegetable  matter,  rock-,  etc.,  should  be  first 
removed  from  the  surface  and  the  holes  filled  in  with  suitable 
material.      The  width   of  the   traveled  way  should  depend  upon 

the  requirements  of  traffic  and  should  ordinarily  be  from  12  to 
is  feet. 

SAND-CLAY  ROADS. 

Natural  sand-elay  road-  may  frequently  be  found  in  localities 
where  the  soil  contains  the  right  proportions  of  sand  and  clay. 
In  sections  of  the  country  where  the  prevailing  subsoil  is  com- 

21  posed  entirely  of  clay,  or,  on  the  other  hand,  is  of  an  extremely 
sandy  character,  these  materials  may  he  properly  mixed  so  as  to 
overcome  the  objectionable  features  of  each,  provided  the  mate- 
rial to  be  added  is  conveniently  available.  Sand-clay  roads  are 
well  adapted  for  light  traffic,  and  when  the  cheapness  of  this 
kind  of  construction  is  considered  it  will  be  seen  that  for  certain 
localities  it  is  preferable  to  macadam.  The  best  sand-clay  road 
is  one  in  which  the  wearing  surface  is  composed  of  grains  of 
sand  in  contact  in  such  a  way  that  the  voids  or  angular  spaces 
between  the  grains  are  entirely  filled  with  clay,  which  act-  as 
a  binder. 

If  natural  drainage  does  not  exist,  artificial  methods  must  be 
used.  The  best  natural  drainage  is  usually  found  upon  a  loose 
gravel  or  a  sandy  soil.  If  the  land  is  dry  and  the  sand  deep 
enough  to  absorb  quickly  the  heaviest  rains,  no  special  attention 
need  be  given  to  drainage  of  sand-clay  roads  other  than  to  pro- 
vide the  proper  crown  to  the  surface  of  the  finished  road  to 
divert  the  water  from  it.  The  roadbed  should  first  be  crowned 
as  nearly  as  possible  to  the  form  desired  in  the  finished  road. 
If  the  clay  is  to  be  placed  upon  -and,  it  will  be  found  more  eco- 
nomical to  crown  first  a  section  of  the  road  nearest  the  source 
of  the  (day.  The  first  load  of  clay  is  dumped  on  this  prepared 
section  at  the  point  nearest  the  clay  bed.  each  succeeding  load 
thus  being  hauled  over  the  preceding.  The  materials  should 
not  be  mixed  in  a  dry  state,  but,  on  the  other  hand,  they  should 
be  thoroughly  mixed  and  puddled  with  water.     This  is  most 


View. 

easily  brought  about  after  a  hard  rain,  the  clay  having  been 
previously  spread  and  the  larger  lumps  broken  up.  The  sur-  22 
face  should  then  be  covered  with  a  few  inches  of  sand  and 
plowed  and  harrowed  thoroughl}7  by  means  of  a  turning  plow 
and  a  cutaway  or  disk  harrow.  In  cases  where  the  plowing  and 
harrowing  are  considered  too  expensive  the  mixing  may  be  left 
to  traffic.  If  the  sand  is  to  be  placed  upon  a  clay  subsoil,  the 
clay  surface  should  be  plowed  and  harrowed  to  a  depth  of  about 
±  inches  and  then  covered  with  6  or  8  inches  of  sand.  Upon 
the  completion  of  the  mixing  and  puddling  the  road  should  be 
shaped  while  it  is  still  soft  enough  to  be  properly  finished  with  23 
a  scraper,  and  at  the  same  time  stiff  enough  to  pack  well  under 
the  roller  or  under  the  action  of  traffic.8 

BURNT-CLAY  ROADS. 

In  large  areas  in  the  South  there  is  little  or  no  sand  to  be 
found,  and  the  clays  are  of  a  particularly  plastic  and  sticky 
variety.  These  clays  may  be  burned  so  as  not  only  to  destroy 
their  plastic  qualities,  but  also  as  far  as  possible  to  form  hard, 
brick-like  lumps  capable  of  sustaining  traffic. 

The  road  is  first  plowed  up  from  ditch  to  ditch;  furrows  are 
then  dug  across  the  road  about  4  feet  apart  and  extending 
through  and  beyond  the  width  to  be  burned.  The  first  course 
of  wood  is  laid  longitudinally,  so  as  to  form  a  series  of  flues  in  24 
which  the  firing  is  started.  Another  layer  of  wood  is  thrown 
irregularly  across  this  floor  in  crib  formation,  with  spaces  left 
between  in  which  the  lumps  of  clay  are  piled.  Then  a  third 
course  of  wood  is  laid  parallel  to  the  first,  and  each  opening 
and  crack  filled  with  brush,  chips,  bark,  small  sticks,  or  any 
other  combustible  material.  A  deep  covering  of  clay  is  finally 
placed  on  top.  The  whole  is  then  tamped  and  rounded  off  so 
that  the  heat  will  be  held  within  the  flues  as  long  as  possible. 
The  fires  are  started  on  the  windward  side,  15  flues  at  a  time.  25 
After  the  burned  surface  is  sufficiently  cooled  to  permit  working 
it  is  smoothed  down  to  form  a  proper  crown  and  rolled.  The  26 
subgrade  is  burned  as  well  as  the  material  above.9 

DUST  PREVENTIVES. 

Tars,  oils,  and  various  other  substances  are  increasing  in  use 
for  road-surface  application.  These  preparations  are  intended 
to  fix  the  wearing  coat  upon  the  road  to  prevent  dust  and  to 
form  a  waterproof  coating.  Owing  to  the  increasing  use  of  27 
motor  vehicles,  treatment  of  this  kind  seems  essential  to  pre- 
serve the  wearing  surface  of  roads  where  there  is  much  of  this 
sort  of  traffic.  The  tar  and  oil  are  sprinkled  upon  the  road  hot;  28 
generally  a  layer  of  sand  or  screenings  is  scattered  on  top. 


I-  • 


8 

The  tarred  roads  arc  hard,  smooth,  and  resemble  asphalt,  except 
that  they  sho*  a  more  gritty  surfaci 

HARD  ROADS. 

(Jkavkl  Roads.     Although  it  Lb  impracticable  and  in  many 

cases  impossible  for  communities  to  build  good  -tone  road-,  a 
surface  of  gravid  may  frequently  he  used  to  advantage,  giving 
far  better  result-  than  could  be  obtained  by  the  use  of  earth 
alone.  Seaside  and  river  gravel,  which  Is  composed  usually  of 
rounded,  water-worn  pebbles,  is  unfit  for  surfacing  roads.  It 
has  no  angular  projections  or  sharp  edges,  and  will  not  bind 
together.  Inferior  qualities  of  gravel  can  sometimes  be  used 
for  foundations,  but  where  it  becomes  necessary  to  employ  such 
material  even  for  that  purpose  it  is  well  to  mix  just  enough 
sandy  or  clayey  loam  to  bind  it  firmly  together.  For  the  wear 
ing  surface  or  the  top  la}Ter  the  pebbles  should,  if  possible,  be 
comparatively  clean,  hard,  angular,  and  tough,  so  that  they  will 
readily  consolidate  and  will  not  be  easily  pulverized  by  the 
impact  of  traffic  into  dust  and  mud.  They  should  be  coarse, 
varying  in  size  from  a  half  inch  to  an  inch  and  a  half. 

The  best  gravel  for  road  building  stands  perpendicular  in  the 
bank;  that  is,  when  the  pit  has  been  opened  up,  the  remainder 
stands  compact  and  firm  and  can  not  be  dislodged  except  by 
the  use  of  a  pick,  and  when  it  gives  way  falls  in  solid  masses. 
Such  material  usually  contains  tough,  angular  gravel,  and  may 
be  placed  on  a  property  prepared  roadbed  without  further 
treatment. 

In  constructing  a  gravel  road  the  roadbed  should  be  first 
brought  to  the  proper  grade;  ordinarily  an  excavation  is  then 
made  to  the  depth  of  8  to  10  inches,  varying  in  width  with  the 
requirements  of  traffic.  The  surface  of  the  roadbed  should 
have  a  fall  from  the  center  to  the  sides  the  same  as  that  to  be 
given  the  finished  road,  and  should  if  possible  be  thoroughly 
rolled  and  consolidated  until  perfectly  smooth  and  firm.  A 
layer  of  good  gravel  not  thicker  than  b'  inches  should  then  be 
29  spread  evenly  over  the  prepared  roadbed.  Next  a  roller  should 
be  used,  or,  if  this  can  not  be  had,  the  road  may  be  thrown  open 
to  traffic  until  it  becomes  fairly  well  consolidated.  If  the  gravel 
is  too  dry  to  consolidate  easily,  it  should  be  kept  moist  by 
sprinkling.  As  soon  as  the  first  layer  has  been  properly  con- 
solidated, a  second  and  if  necessary  a  third  layer,  each  about  6 
inches  thick.  Is  spread  on  and  treated  in  the  same  manner  until 
the  road  i-  built  up  to  the  required  thickness  and  cross  section. 
The  last  or  surface  layer  should  be  rolled  or  left  to  be  consoli- 
dated until  the  wheels  of  heavily  loaded  vehicles  pa— ing  over 
it  make  no  visible  impression.11 


9 


View 


Shell  Roads.— In  many  of  the  Eastern  and  Southern  States 
road  stones  are  not  available,  nor  is  it  possible  to  secure  good 
coarse  gravel.  Oyster  shells  can  be  secured  cheaply  in  most  of 
these  States,  and  when  applied  in  a  layer  of  0  inches  and  rolled, 
with  a  similar  top  layer,  directly  upon  sand  or  sandy  soil,  form 
excellent  roads  for  light  traffic.  Shells  wear  much  more  rap- 
idly than  broken  stone  or  gravel  of  good  quality,  and  conse- 
quently roads  made  of  them  require  more  constant  attention  to 
keep  them  in  good  order.12 

Stone  Roads. — For  ordinar}T  country  roads  experience  has 
shown  that  the  broken-stone  way  need  not  be  more  than  from 
12  to  15  feet  wide,  if  suitable  shoulders  3  to  5  feet  wide  are  built 
on  each  side  of  the  stone.  The  modern  practice  is  to  make  the 
macadam  surface  as  thin  as  possible,  yet  with  sufficient  body  to 
stay  in  place,  the  theory  being  that  the  macadam  is  only  a  wear- 
ing surface.  Three  inches  of  macadam,  after  rolling,  is  the 
least  thickness  which  is  practicable,  and,  except  in  unusual  cases, 
a  depth  greater  than  6  inches  after  rolling  is  rarely  necessary, 
if  the  foundation  is  suitable.  The  material  of  the  foundation  is 
of  much  importance.  It  should  be  composed  of  porous  material 
free  from  clay  or  loam  and  sufficiently  strong  to  sustain  any 
load  likely  to  come  upon  it. 

The  principal  qualities  necessary  in  road-building  stones  are 
hardness  and  toughness.  Trap  rock  has  long  been  considered 
the  best  material  for  macadam  purposes,  but,  except  in  certain 
localities,  these  stones  are  not  common.  Stone  from  a  ledge, 
because  of  its  unif ormitjr  in  desirable  qualities,  is  usually  better 
than  field  stone  and  makes  a  smoother  and  more  durable  road, 
but  if  the  ledge  is  of  an  inferior  grade  of  rock  it  should  not  be 
used  merely  because  it  is  ledge  in  preference  to  field  stone  of  a 
better  quality  of  rock. 

Tools  and  Machinery. — In  addition  to  the  shovels,  picks,  and 
other  ordinary  implements  of  construction,  a  considerable  out- 
lay for  machinery  is  necessary.  Portable  stone-crushing  out- 
fits may  be  bought  at  prices  ranging  from  $1,600  to  $2,500  and  3tv 
are  well  adapted  for  country  use.  From  80  to  100  tons  (60  to 
80  cubic  yards)  of  broken  stone  per  day  may  reasonably  be 
expected  if  the  plant  is  kept  in  good  condition.  Steam  road 
rollers  are  now  used  to  a  great  extent.  Macadam  roads  may 
of  course  be  built  with  rollers  drawn  by  horses;  they  may  also 
be  built  without  any  rolling  other  than  results  from  the  wheels 
of  moving  vehicles.  There  are  several  excellent  makes  of  steam 
rollers  which  may  be  had  at  prices  ranging  from  $2,500  to 
$3,500.  Since  water  is  always  needed  in  rolling  macadam,  a 
watering  cart  or  sprinkler  should  be  provided  with  a  capacity 
of  from  450  to  600  gallons.     A  road  machine  is  a  most  service- 


1(1 


able  implement   in  shaping  and  repairing  earth  roads  ami  in 
;;j       preparing  the  foundation  for  macadam  roads. 

The  importance  of  proper  grades  atul  drainage  for  all  roads 
ha-  already  been  mentioned.  It  i-  not  enough  that  the  road- 
way for  a  macadam  road  shall  he  graded  with  reasonable  care. 
The  surface  upon  which  the  broken  stones  arc  to  be  placed 
must  be  hard,  smooth,  and  carefully  crowned.  It'  the  founda- 
tion Lfi  not   hard  and  firm,  the   -tone-  will  he   pressed  into   it    by 

the  roller  and  wasted.     Usually  a  trough-shaped  -ret  ion  is  made. 
sufficient  material  being  left  on  the  sides  to  form  shoulders  for 

32  the  macadam.  After  the  roadbed  is  shaped  to  the  approximate 
cross  Bection  it  should  he  rolled  thoroughly  until  it  i-  hard, 
firm,  and  smooth. 

Stones  ranging  in  diameter  from   1  j  to  2\  inches  Bhould  he 

33  spread  first  for  the  lower  course,  to  a  depth  which  will  allow 
for  a  shrinkage  of  35  per  cent  under  the  roller.      Wnen  loo  feet 

34  or  so  of  the  first  course  of  stone  has  been  spread,  the  rolling 
should  begin.  It  will  he  found  best  to  begin  the  rolling  at  the 
outer  edge  of  the  macadam,  running  upon  the  shoulder  a  few 
inches.     The   second   course,   consisting  of    stones   varying    in 

35  diameter  between  ^  inch  and  1|  inches,  should  be  spread  and 
rolled  as  was  the  lower  course.     After  the  stones  are  thoroughly 

3(3  compacted  the  binder  should  be  spread.  This  top  cour>c  is 
usually  a  little  more  than  1  inch  in  depth  in  6-inch  work.     The 

37  watering  cart  should  then  be  put  on  in  advance  of  the  roller 
and  as  much  as  possible  of  the  du^t  flushed  into  the  interstices 

38  between  the  stones.  The  roadway  should  be  wet  and  rolled 
until  it  puddles  on  the  surface,  showing  that  the  voids  are  sub- 
stantially tilled. 

All  trees  which  are  ornamental  or  which  are  of  value  as  shade 
trees  should  be  preserved  and  protected.  They  are  a  consider- 
able factor  in  reducing  the  cost  of  maintenance,  since  they 
lessen  the  evaporation  of  the  moisture  from  the  macadam. 
They  add  greatly  to  the  attractiveness  of  the  road.  A  good 
arrangement  for  trees  with  large  tops  is  to  set  them  about  50 
feet  apart  on  each  side  of  the  road,  but  alternated,  so  that  there 
will  be  a  tree  every  -■>  feet  along  the  road.1 

39  MAINTENANCE. — Some  one  has  said  that  the  maintenance  of  a 
macadam  road  should  begin   on  the  day  the   road  is  completed. 

40  and  this  IS  true  of  all  types  of  roads.  The  mistake  is  often 
made  of  building  a  line  road  and  then  allowing  it  to  go  to  ruin. 

4  1  It  i-  usually  not  necessary  to  do  much  to  the  macadam  surface 
for  a  year  or  two  except  to  till  any  small  holes  or  incipient  ruts 
which  may  occur.  It  i<  well  to  have  piles  oi  material  for  mend- 
ing the  road  placed  at  convenient  intervals  along  its  length. 


11 

ROAD  ADMINISTRATION. 

The  administration  of  the  road  funds  of  any  community,  to  be  suc- 
cessful, must  be  conducted  along  business  lines.  When  we  consider 
that  there  are  in  round  numbers  2,152,000  miles  of  public  roads  in  the 
United  States  and  that  approximately  $80,000,000  are  expended  upon 
them  every  year,  we  realize  that  so  large  a  sum  should  be  carefully 
spent  and  in  accordance  with  business  principles.14  In  the  first  place, 
road  administration  should  be  free  from  political  influence.  Secondly, 
men  specially  trained  for  their  work  are  essential.  It  seems  to  be  a 
popular  opinion  that  any  one  can  build  a  road  and  that  special  train- 
ing is  unnecessary,  and  yet  no  man  in  building  a  house  would  dream 
of  hiring  painters  to  lay  the  brick  and  bricklayers  to  do  the  painting. 
This  is  the  reason  statute  labor  is  inefficient.  Each  man  does  his 
share  of  the  work  ignorantly  and  grudgingly,  and  is  not  required  to 
have  any  knowledge  of  road  construction. 

A  good  system  would  be  to  have  a  highway  engineer  competent  to 
pass  upon  any  question  affecting  the  construction  or  maintenance  of 
roads  placed  in  charge  of  the  road  work  of  the  county.  He  should 
report  directly  to  the  county  court.  This  engineer  should  be  respon- 
sible for  road  construction;  for  the  repair  and  maintenance  of  roads; 
should  prepare  contracts  and  specifications;  repair  and  maintain 
bridges;  have  charge  of  all  road  machinery  and  purchase  all  material, 
and  should  account  regularly  to  the  county  court  for  all  money 
expended  under  his  direction.  If  one  county  could  not  afford  to 
employ  an  engineer,  two  or  three  counties  might  share  the  expense 
and  the  benefits.  Under  this  engineer's  immediate  jurisdiction  should 
be  placed  a  certain  number  of  skilled  road  supervisors  or  road  over- 
seers, each  having  a  given  territory  for  which  he  is  responsible.  In 
his  territory  the  overseer  should  have  direct  supervision  over  every 
road  gang,  and  each  gang  should  be  in  charge  of  a  foreman.  Under 
this  system  of  organization  there  would  be  no  waste  of  public  reve- 
nues in  ill-conducted  efforts  at  road  building,  for  every  item  of  work 
performed  would  be  a  part  of  a  general  system  devised  in  the  office  of 
the  highway  engineer  and  approved  by  the  county  court. 

In  some  cases  it  might  be  found  better  to  centralize  the  road  work 
and  authority  of  the  State  under  direction  of  a  State  engineer,  with 
his  corps  of  assistant  engineers  acting  in  lieu  of  the  county  engineers 
described  in  the  last  paragraph.  This  State  system  would  probably 
have  the  advantage  of  less  aggregate  outlay  for  engineers  and  pro- 
vide a  more  methodical  system  of  county  roads;  but  on  the  other 
hand  there  would  be  lacking  an  intimate  knowledge  of  local  needs  and 
conditions  which  would  be  possessed  by  the  county  engineer.  The 
State  system  would  also  weaken  in  a  measure  local  authority  over 
roads. 


AITKNDIX. 


LANTERN   SLIDES. 

1 .  One  bale  of  cotton  hauled  with  difficulty. 

Taken  by  S.  C.  Lancaster,  Office  of  Public  Roads. 

2.  Eleven  bales  of  cotton  hauled  on  same  road  as  in  No.  1   after  it  had  been 

improved. 

Taken  by  S.  C.  Lancaster,  Office  of  Public  Roads. 

3.  A  rise  of  value  in  real  estate  due  to  an  improved  road. 

The  owner  of  this  land  gave  up  living  on  it  because  of  the  bad  road  and  sold  it  for 
$1,500  to  the  present  owner.  A  short  time  after  the  sale  the  road  was  improved  as  shown 
in  the  picture,  and  the  first  owner  offered  to  buy  it  back  for  83,000.  This  was  refused. 
He  afterwards  offered  $5,000  for  the  farm  and  was  again  refused.  The  first  owner  lived 
in  the  little  cabin,  but  the  purchaser  built  himself  a  good  home. 

Taken  by  S.  C.  Lancaster,  Office  of  Public  Roads. 

4.  Clay  road  before  improvement. 

From  U.  S.  Dept.  Agr.,  Office  of  Public  Roads  Bui.  27,  PI.  I. 

•">.  Same  road  as  in  No.  4  after  improvement. 

C>.  The  road  should  be  well  located,  with  easy  curves. 

7.  A  well-located  road  on  a  sidehill. 

8.  Crown  on  earth  road. 

9.  Road  with  center  lower  than  sides  and  consequent  formation  of  mud  holes. 

10.  Side  drain  under  construction. 

From  U.  S.  Dept.  Agr.,  Office  of  Public  Roads  Bui.  29,  PI.  III. 

1 1 .  Concrete  culvert. 

12.  Perspective  view  of  split-log  drag. 

13.  Plan  and  elevation  of  split-log  drag. 

14.  Road  before  dragging. 

1 5.  Side  viewr  of  drag. 

1  ( > .     Drag  in  use. 

17.  Rear  view  of  drag. 

18.  Road  after  dragging. 

19.  Road  in  Arkansas  before  draggiiiL' 

20.  Same  road  as  in  No.  19  after  having  been  dragged  for  one  year. 

2  I.  Sandy  road  difficult  to  travel  over. 

From  U.  S.  Dept.  A-r.,  <  HVue  of  Public  Roads  Bui.  27,  PI.  I. 

L'*J.     ^and-clay  road  in  process  of  construction. 

From  U.  S.  Dept.  Agr.,  Office  of  Public  Roads  Bui.  J7.  PI.  II. 

23,  Finished  sand-clay  road. 

-  1 .  First  cMursi'  of  wood  laid  across  trenches.     |  In  foreground.) 

25.  Pile  of  day  and  wood  completed  and  firing  started. 

26.  Surface  of  burnt  clay  smoothed  and  crowned. 

(12) 


13 

No.  of 
view. 

27.  Dust  raised  by  automobile  going  at  high  speed. 

28.  Tar  poured  on  road  and  spread  with  brooms. 
29;     Finished  gravel  road. 

30.  Portable  crushing  plant,  including  stone  crusher,  engine,  and  boiler,  portable 

bins,  revolving  screen,  and  elevator  to  lift  the  stone  after  it  is  broken  and  to 
discharge  it  into  the  screen. 

From  U.  S.  Dept.  Agr.,  Office  of  Public  Roads  Bui.  29,  PI.  II. 

31.  Preparing  subgrade  with  road  machine  drawn  by  traction  engine. 

32.  Subgrade  of  road  being  rolled  to  make  it  hard  and  smooth. 

33.  First  course  of  stone. 

34.  Showing  placing  of  first  course  of  stone. 

35.  Second  course  of  stone. 

36.  Second  course  after  rolling. 

37.  Binder  course. 

38.  Completed  road  surface. 

39.  Road  in  Missouri  in  almost  impassable  condition. 

40.  The  transformation  wrought  by  an  improved  highway. 

41.  Showing  variety  of  traffic  over  a  well-built  road. 

Taken  by  S.  C.  Lancaster,  Office  of  Public  Roads. 


i:i:ikim:x(  E8. 


I. 

4. 
6. 

9. 
10. 
11. 
12. 
13. 
14. 


46. 


T.  8.  Dept  Alt..  Bureau  of  Statistics  Bui.  49,  p.  13. 
Byrne,  Austin  T..    "Treatise  on  highway  construction. 
a  York.  1902. 

U.  > 

u.  S 

I".  - 


p.  4.     John  Wiley  and 


11. 


p.  13. 


Dept.  Agr.,  Bureau  ol  Statistics  Bol  49,  p. 
Dept  Agr.,  Office  of  Public  Roads  Bol  32. 

Dept  Agr.,  Bureau  of  Stati-tirs  BoL  4:!.  p. 
Dept  Agr.,  Office  of  Public  Roads  Bui.  32. 
Dept  Agr.,  Office  of  Public  Roads  Bui.  - 
Dept.  Agr.,  Office  of  Public  Roads  Bui.  27. 
3.  I  tept  Agr.,  Office  of  Public  Roads  Bui.  27. 
-    I  kept  Agr.,  Office  ol  Public  Roads  Circ.  47. 
i  .  8.  Dept  Agr..  Fanners'  BoJ 
1      S.  Dept  Agr.,  Fanners'  Bui.  95. 

8  Dept  Alt..  Office  of  Public  Roads  Bui.  29,  p.  23. 
&  e  Appendix,  Public  road  mileage  and  expenditures. 
Office  of  Public-  Roads  Bui. 


From  V.  B.  Dept.  Agr., 


fca  and  bulletin*  upon  roads  and  road 

Making  and  Maintenance.     By  Tbomas  Aitken.    Charles  Griffin  A  Co..  London. 
American  Highways.     By  X.  S.  Shaler.     The  Century  Company,  New  York. 
A  Treatise  on  Roads  and  Pavements.     By  Ira  O.  Baker.     John  Wiley  a.  Bona,  New 

Soft. 
A  Text-book  on  Roads  ami  Pavements.     By  Frederick  P.  Bpalding.     John  Wiley  & 
\v  York. 
B:  Their  Construction  and  Maintenance.     By  Allan  Greenwell  and  J.  V.  Elsden. 
D.  Fourdrinier,  London. 

-  and  Pavements  in  France.     By  A.  P.  Rockwell.     John  Wiley  &  Sons.  New 
rk. 
The  Construction  of  Roads,   Paths,   and  Bee    Defenses,      by    Frank    fatham.     The 

nitary  Publishing  Company ,  London. 
Highway  Construction   in   Wisconsin.     Wisconsin  <  reological  and   Natural  History 

Survey  Bui.  10. 
Kural  Highways  of  Wisconsin.     Wisconsin  Geological  and  Natural  History  Survey 
bul.    I 

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UNIVERSITY  OF  FLORIDA 

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3  1262  08929  2030 


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